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Within an isospin- and momentum-dependent transport model, we investigate the necessity of selfconsistent calculations for the electromagnetic field in probing the nuclear symmetry energy using pion observables in heavy-ion collisions at intermediate energies. To this end, we perform the $^{96}$Ru + $^{96}$Ru collisions at 400 MeV/nucleon with two calculations scenarios for the electromagnetic field including the selfconsistent calculation and the most used Li\'{e}nard-Wiechert formula, while the latter is a simplified one of the complete Li\'{e}nard-Wiechert formula by neglecting the radiation field for practical calculations in heavy-ion collisions at intermediate and/or relativistic energies. As a comparison, we also consider the static Coulomb field formula for calculations of the electromagnetic field in heavy-ion collisions. It is shown that the most used simplified Li\'{e}nard-Wiechert formula is not enough for the electromagnetic field calculation because the absent radiation field in this formula also affects significantly the charged pions as well as their $\pi^{-}/\pi^{+}$ ratio. Moreover, we also examine effects of the electromagnetic field in these scenarios on the double $\pi^{-}/\pi^{+}$ ratio of two isobar reaction systems of $^{96}$Ru + $^{96}$Ru and $^{96}$Zr + $^{96}$Zr at 400 MeV/nucleon. It is shown that the double $\pi^{-}/\pi^{+}$ ratio of two reactions tends to be less affected by the electromagnetic field calculation scenario and thus can still be an effective probe of the nuclear symmetry energy in heavy-ion collisions. Therefore, according to these findings, it is suggested that the selfconsistent calculation for the electromagnetic field should be carefully taken into account when using the pion observables to probe the nuclear symmetry energy in heavy-ion collisions., Comment: 7 pages, 6 figures. Accepted for publication in Physical Review C

A simple high-performance liquid chromatography (HPLC) method coupled with principal component analysis (PCA) and hierarchical cluster analysis (HCA) was developed for distinguishing Astragali Radix from its adulterants. Five species, including A. membranaceus var. mongolicus, A. membranaceus, H. polybotrys, A. chrysopterus and A. ernestii, were analyzed by this method. At the same time, four major bioactive isoflavonoids, namely calycosin-7-O-D-glucopyranosidc, ononin, calycosin and formononetin, were simultaneously determined in Astragali Radix. This method was proven to have good precision, repeatability, stability and recovery. It was successfully applied to distinguish Astragali Radix from its adulterants species and can be used for the quality control of Astragali Radix.

Within a transport model using as the input nucleon momentum profiles from a parameterized isospin-dependent single-nucleon momentum distribution with a high momentum tail induced by short-range correlations, we employ the $^{197}$Au + $^{197}$Au collisions at 400 MeV/nucleon to examine on one hand effects of the short-range correlations on the pion and flow observables in probing the nuclear symmetry energy, and on the other hand how reliable are this isospin-dependent single-nucleon momentum distribution as well as the corresponding parameter settings. Besides significant effects of the short-range correlations on the pion and flow observables are observed, we also find that the theoretical simulations of $^{197}$Au + $^{197}$Au collisions with this momentum distribution using two sets of parameters extracted from the experimental analysis and the self-consistent Green's function prediction, respectively, can reproduce the neutron elliptic flows of the FOPI-LAND experiment and the $\pi^{-}/\pi^{+}$ ratios of the FOPI experiment under the symmetry energy setting in a certain range. Therefore, we conclude that this parameterized isospin-dependent single-nucleon momentum distribution is reliable for the isospin-asymmetric nuclear matter, correspondingly, two sets of parameters extracted from both the experimental analysis and the self-consistent Green's function prediction can not be ruled out according to the available experimental information at present., Comment: 10 pages, and 9 figures, published version to meet the journal's style

The impact parameter dependence ofπ-/π+ratio is examined in heavy-ion collisions at 400 MeV/nucleon within a transport model. It is shown that the sensitivity ofπ-/π+ratio on symmetry energy shows a transition from central to peripheral collisions; that is, the stiffer symmetry energy leads to a largerπ-/π+ratio in peripheral collisions while the softer symmetry energy always leads this ratio to be larger in central collisions. After checking the kinematic energy distribution ofπ-/π+ratio, we found this transition of sensitivity ofπ-/π+ratio to symmetry energy is mainly from less energetic pions; that is, the softer symmetry energy gets the less energetic pions to form a smallerπ-/π+ratio in peripheral collisions while these pions generate a largerπ-/π+ratio in central collisions. Undoubtedly, the softer symmetry energy can also lead more energetic pions to form a largerπ-/π+ratio in peripheral collisions. Nevertheless, considering that most of pions are insufficiently energetic at this beam energy, we therefore suggest theπ-/π+ratio as a probe of the high-density symmetry energy effective only in central at most to midcentral collisions, thereby avoiding the possible information of low-density symmetry energy carried inπ-/π+ratio from peripheral collisions.

Within the isospin- and momentum-dependent transport model IBUU11, we examine the relativistic retardation effects of electrical fields on the $\pi^{-}/\pi^{+}$ ratio and neutron-proton differential transverse flow in heavy-ion collisions at intermediate energies. Compared to the static Coulomb fields, the retarded electric fields of fast-moving charges are known to be anisotropic and the associated relativistic corrections can be significant. They are found to increase the number of energetic protons in the participant region at the maximum compression by as much as 25\% but that of energetic neutrons by less than 10\% in $^{197}$Au+$^{197}$Au reactions at a beam energy of 400 MeV/nucleon. Consequently, more $\pi^{+}$ and relatively less $\pi^{-}$ mesons are produced, leading to an appreciable reduction of the $\pi^{-}/\pi^{+}$ ratio compared to calculations with the static Coulomb fields. Also, the neutron-proton differential transverse flow, as another sensitive probe of high-density symmetry energy, is also decreased appreciably due to the stronger retarded electrical fields in directions perpendicular to the velocities of fast-moving charges compared to calculations using the isotropic static electrical fields. Moreover, the retardation effects on these observables are found to be approximately independent of the reaction impact parameter., Comment: 10 pages, 9 figures

Using an isospin- and momentum-dependent transport model, we examine the effects of an electric field induced by a variable magnetic field on the ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio in central to peripheral heavy-ion collisions at beam energies of 400 and 1500 MeV/nucleon. It is shown that while the induced electric field does not affect the total multiplicities of both ${\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\pi}}^{+}$ mesons at both the lower beam energy of 400 MeV/nucleon and the higher beam energy of 1500 MeV/nucleon, it reduces (enhances) the emission of ${\ensuremath{\pi}}^{\ensuremath{-}}\phantom{\rule{0.16em}{0ex}}({\ensuremath{\pi}}^{+})$ mesons in midrapidity, but enhances (reduces) the emission of ${\ensuremath{\pi}}^{\ensuremath{-}}\phantom{\rule{0.16em}{0ex}}({\ensuremath{\pi}}^{+})$ mesons in forward and backward rapidities especially for the more peripheral collisions at the lower beam energy because of the rapidly transient variable magnetic field at more peripheral collisions and the longer reaction duration time at the lower beam energy. These findings indicate that the total ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio is still a precisely reliable probe of symmetry energy at both the lower and the higher beam energies, but one should consider the induced electric field when using the differential ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio to probe the symmetry energy especially for the lower beam energy and more peripheral collisions. Finally, the relative suppression factor based on the ratio of ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ in different rapidities is proposed to be an effective probe of the induced electric field generated in heavy-ion collisions due to its maximizing effects of induced electric fields on the differential ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio but minimizing effects of some uncertainty factors in heavy-ion collisions.

The impact parameter dependence of π-/π+ ratio is examined in heavy-ion collisions at 400 MeV/nucleon within a transport model. It is shown that the sensitivity of π-/π+ ratio on symmetry energy shows a transition from central to peripheral collisions; that is, the stiffer symmetry energy leads to a larger π-/π+ ratio in peripheral collisions while the softer symmetry energy always leads this ratio to be larger in central collisions. After checking the kinematic energy distribution of π-/π+ ratio, we found this transition of sensitivity of π-/π+ ratio to symmetry energy is mainly from less energetic pions; that is, the softer symmetry energy gets the less energetic pions to form a smaller π-/π+ ratio in peripheral collisions while these pions generate a larger π-/π+ ratio in central collisions. Undoubtedly, the softer symmetry energy can also lead more energetic pions to form a larger π-/π+ ratio in peripheral collisions. Nevertheless, considering that most of pions are insufficiently energetic at this beam energy, we therefore suggest the π-/π+ ratio as a probe of the high-density symmetry energy effective only in central at most to midcentral collisions, thereby avoiding the possible information of low-density symmetry energy carried in π-/π+ ratio from peripheral collisions.

Chromatographic fingerprinting has been widely accepted as a crucial method for qualitative and quantitative analyses of bioactives within traditional Chinese medicine. A fingerprint provides detailed information, specific for any given herb, thus facilitating the quality control measures of a given traditional Chinese medicine. In this article, quality assessment of Radix Scrophulariae was achieved by using high performance liquid chromatography combining diode-array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI/MS). Eight batches of sample obtained from different origins in China were used to establish the fingerprint and quantitative analyses. By comparing the retention times, UV and MS spectral data with reference standards, four characteristic peaks in the chromatograms were confirmed as corresponding to acetoside, angoroside C, cinnamic acid, and harpagoside. In addition, other two characteristic peaks were tentatively identified, following the literature interpretation of HPLC-ESI-MS and LC-MS/MS (affording structural information) to be sibirioside A and scrophuloside B(4), respectively. The results indicated that the newly developed HPLC-DAD-MS fingerprint method would be suitable for quality control of Radix Scrophulariae.

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r2 >0.9995 for all the investigated analytes), satisfactory precision (RSD

Within the framework of the Dirac theory, the relativistic bound states for the trigonometric Poschl-Teller (PT) potential are obtained in the case of spin symmetry. It is found from the numerical results that there exist only positive energy states for bound states in the case of spin symmetry. Also, the energy levels approach a constant when the potential parameter α goes to zero. The special case for equally scalar and vector trigonometric PT potential is also studied briefly.

The structures, relative stability and charge distributions in the maximum-spin n +1 Li n −1 X and n Li n −1 X + ( n =2–7, X = Li, Na and K) clusters have been studied with density functional calculations. We predicted the existence of a number of previously unknown cationic isomers. Our results revealed that all high-spin Li n −1 X clusters can be derived from capping an X atom over the high-spin Li n −1 . Larger heter-atoms favor to occupy outer positions in order to decrease geometrical reconstruction. The high-spin bimetallic clusters tend to holding three-dimensional geometry rather than planar form in low-spin situations whereas smaller ions adopt linear-like form to reduce their repulsive force among atoms. In various high-spin Li n −1 X (X = Li, Na and K, n = 2–8) neutral and cationic species, 5 Li 3 X and 3 Li 2 X + are predicted to be of high stability, which can be explained by valence bond theory.

Three new hydroxylated xanthones with prenyl or geranyl substituents, compounds 1-3, were isolated from the twig bark of Garcinia xanthochymus, along with the four known compounds 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone (4), 1,3,5,6-tetrahydroxy-4,7,8-triprenylxanthone (5), garciniaxanthone E (6), and 6-prenylapigenin (7). Their structures were elucidated by extensive spectroscopic analysis, including 1D- and 2D-NMR as well as HR-MS experiments. All compounds showed moderate cytotoxicities against breast cancer (MDA-MB-435S) and lung adenocarcinoma (A549) cell lines, but lacked antifungal activity against Candida albicans.

Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.

The current situation of human measurement technology and the shortage of the practical methods are discussed in the thesis. A measurement method based on small sample is given. With the measuring data, it establishes a computer-aided human body biomechanical model in AnyBody modeling system. Finally, some problems of the application of the small sample method in human factors engineering are discussed.

The hip of Rosa multiflora Thunb. has been traditionally used as a dietary supplement and a herbal remedy for the treatment of various diseases including cold, flu, inflammation, osteoarthritis, rheumatoid arthritis and chronic pain in China.To explore the anti-inflammatory ingredient of the hip of R. multiflora Thunb. and its mechanism of action.The ethanol extract of the hip of R. multiflora Thunb. was fractioned with petroleum ether, ethyl acetate and water, and each fraction was screened for anti-inflammatory activity in xylene-induced mouse ear edema model. Three more models, acetic acid-induced mouse vascular permeation, cotton pellet-induced rat granuloma, and carrageenan-induced rat hind paw edema were also employed to verify the anti-inflammatory effect of the identified fraction. To explore the mechanism of action, the activity of inducible nitric oxide synthase (iNOS) and the level of nitric oxide (NO) in sera, as well as mRNA expression level of cyclo-oxygenase-2 (COX-2) in inflammatory tissues of rats with carrageenan-induced hind paw edema were measured. GC-MS technology was applied to identify the active components in the active fraction.The petroleum ether fraction (PEF) was identified to be the active fraction in inflammation animal models (i.e., oral administration of PEF (168.48, 42.12 and 10.53 mg/kg) evoked a significantly (P0.001) dose-dependent inhibition of the xylene-induced mice ear edema). Down-regulating COX-2 expression (P0.001) and reducing NO production (P0.05) through inhibiting iNOS activity (P0.001) may be the partial mechanism of action of PEF. GC-MS analysis indicated that unsaturated fatty acids are enriched in PEF and may be responsible for the anti-inflammatory activity of PEF and this herb. The results of this study provide pharmacological and chemical basis for the application of the hip of R. multiflora Thunb. in inflammatory disorders.

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r(2)0.9995 for all the investigated analytes), satisfactory precision (RSD1.51%) and good recovery (from 97.64 to 101.16%). The established method was successfully applied to simultaneous determination of nine nucleosides and nucleobases in 61 batches of samples from 13 Fritillaria species collected from different habitats in China, which could be helpful to control the quality of Fritillaria bulbs.

The aim of this study was to look for the chemical constituents from the rhizomes of Dryopteris sublaeta. The fresh plant was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate and n-butanol. The fraction of ethyl acetate was repeatedly chromatographied over silica gel and Sephadex LH-20 columns. Structures of pure compounds were established on the basis of their physiochemical and spectral data. Nine compounds were obtained and identified as sublaetentin A (1), sublaetentin B (2), sublaetentin C (3), sublaetentin D (4), matteuorienate A (5), matteuorienate C (6), arbutin (7), 3-methoxy-4-hydroxyphenyl-1-O-beta-D-glucopyranoside (8) and 3,4-dimethoxyphenyl-1-O-beta-D-glucopyranoside (9). Compounds 1 - 4 are new compounds, the others were isolated from this plant for the first time.

To study the chemical constituents of Dryopteris sublaeta Ching et Hsu.Fresh plant of Dryopteris sublaeta ching et hsu was extracted twice with boiling water, concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ethyl acetate extract was chromatographed over macroporous adsorption resin (Diaion HP-20) eluted with a mixture of H2O and MeOH in increasing MeOH content. Their fractions from resin were repeatedly chromatographed over Toyopearl HW-40, Sephadex LH-20 and silica gel column chromatography. The compounds were identified on the basis of their physiochemical and spectral data.Four compounds were obtained and identified as 3,5-dihydroxy-stilbene-3-O-neohesperidoside (1), 3,5-dihydroxy-stilbene-3-O-beta-D-glucoside (2), polydotin peceid (3) and 3,5,4'-trihydroxy-bibenzyl-3-O-beta-D-glucoside (4).Compound 1 is a new compound, the others were isolated from Dryopteris for the first time.

To study the chemical constituents of Dryopteris sublaeta Ching et Hsu.Fresh plant of Dryopteris sublaeta Ching et Hsu was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ether extract was chromatographed over silica gel column. The compounds were identified on the basis of their physiochemical and spectral data.Four compounds were obtained and identified as 2 (S)-5, 7, 3'-trihydroxy-6, 8-dimethyl-5'-methoxyflavanone (1), matteucinol (2), desmethoxymatteucinol (3) and 5, 7, 2'-trihydroxy-6, 8-dimethylflavanone (4).Compound 1 is a new one, the others were isolated from Dryopteris for the first time.

We study the scattering states of the screened Coulomb potential in the nonrelativistic frame. The explicitly calculation formula of phase shift is derived and the normalized radial wave functions of scattering states on the scale are presented. By studying analytical properties of scattering amplitude the screening effects on bound states are discussed numerically. It is shown that the screening effects increase with increasing screened parameter, especially for large quantum states.